An apparatus or combination of operational equipment 1 for effecting liquid or gas communication to, from or between at least one gas and/or liquid containing source 3a,b. The at least one source 3a,b having an upper boundary 5 through which an access well 20 is drilled. The access well 20 extending downwardly to a location within the reservoir 3a,b. The access well 20 also drilled laterally within the at least one source 3a,b. The upper boundary 5 being a transition 5 in phase or composition of solids, liquids or gases underground such as a transition between clay 7 and shale 9. The apparatus or combination of operational equipment 1 including a jetting device 10 for insertion into the access well 20. The jetting device 10 adapted to jet multiple boreholes 22 from a lateral portion 21a of the access well at multiple radial orientations 23 around the lateral portion 21a relative to a vertical.

A method for operating a kerogen-rich unconventional gas reservoir characterized by there being multiple hydraulically-fractured wells drilled thereinto comprises: recovering a methane-containing gas from a first hydraulically-fractured well drilled into the gas reservoir, steam-methane reforming the recovered methane-containing gas to yield a hydrogen gas and an inorganic carbon-containing gas, injecting at least a portion of the hydrogen gas into a second hydraulically-fractured well drilled into the gas reservoir, and injecting at least a portion of the inorganic carbon-containing gas into a third hydraulically-fractured well drilled into the gas reservoir.

A full-length screen pipe hole protection device and method with pressurized hole packing in a soft coal seam relates to the field of gas drainage technologies. The device includes a grouting system, a drainage system and a hole fixing system. The grouting system injects a pressurized sealing material into a borehole through a pressure pump to increase a sealing effect of the borehole. The drainage system drains gas in the middle of air holes on metal baffle plates and hole fixing screen pipes through a drainage pipe to increase flowability of gas. The hole fixing system is inside the borehole and fixed with the metal baffle plates, and the hole fixing screen pipes are fixedly connected with each other through fitting mouths and fitting buckles. The device is fixedly mounted in the gas drainage borehole. After hole packing, the drainage pipe is connected with a drainage pump to drain gas.

A multi-level cross-district surface well pattern deployment method is provided. Firstly, a first horizontal well is drilled from a location on a land surface corresponding to a junction H.sub.1 of a district rise coal pillar of the first district C.sub.1 in a first level and an upper mine field boundary coal pillar. A multilateral well is drilled from a location on the land surface corresponding to a junction H.sub.3 of a level coal pillar between the first and second levels, and the district rise coal pillar of the first district C.sub.1 in the first level. Liquid nitrogen is injected for permeability improvement after a gas drainage quantity decreases to 20% of an initial quantity. Gas drainage is repeated multiple times until the drainage quantity of coal bed methane through a gas drainage pipe of the horizontal pipe is reached 3 m.sup.3/min.

A method for operating a kerogen-rich unconventional gas reservoir characterized by there being multiple hydraulically-fractured wells drilled thereinto comprises: recovering a methane-containing gas from a first hydraulically-fractured well drilled into the gas reservoir, steam-methane reforming the recovered methane-containing gas to yield a hydrogen gas and an inorganic carbon-containing gas, injecting at least a portion of the hydrogen gas into a second hydraulically-fractured well drilled into the gas reservoir, and injecting at least a portion of the inorganic carbon-containing gas into a third hydraulically-fractured well drilled into the gas reservoir.

Methods and systems for gasifying coal are disclosed herein. In some embodiments, a representative coal gasification system can comprise (i) an injection well extending from a ground surface to an underground coal gasification (UCG) reaction region of a coal seam; (ii) a production well spaced apart from the injection well and extending from the ground surface to the UCG reaction region, and (iii) conduits each extending from the ground surface to areas of the coal seam. End portions of the conduits within the coal can be laterally peripheral to the UCG reaction region. The conduits are configured to deliver a primary fluid from the ground surface to the primary region, the injection well is configured to deliver an oxidant gas to the UCG reaction region, and the production well is configured to deliver the product gas from the UCG reaction region to the ground surface.

This invention provides a composition and a method for increasing biogenic methane gas production from subterranean coal deposits. The composition and method provides a nutrient protein hydrolysate that contains less than 0.5 percent of the amino acid L-tyrosine, which is most effective in significantly increasing methane gas released from subterranean coal deposits.

A steeply-inclined ultra-thick coal seam gas control method based on a binary composite liquid. The method includes taking a clean fracturing fluid system and a microemulsion as a binary composite liquid. The method includes injecting the binary composite liquid into a coal mass by means of a main hydraulic fracturing and permeability improvement method of hydraulic fracturing and water jet slotting to form a coal mass gas extraction system of binary composite liquid fracturing and permeability improvement. The method includes investigating and analyzing a gas control effect of the steeply-inclined ultra-thick coal seam according to change characteristics and analysis of gas extraction flow rate, change characteristics and analysis of permeability coefficient of coal seam, change characteristics and analysis of gas natural desorption speed of coal mass, change characteristics and analysis of gas concentration of return air flow of working face and theoretical analysis of drilling cuttings index.

A method for extracting gas by fracturing a coal seam through a combination of hydraulic slotting and multi-stage combustion impact wave comprises cutting slots in an impact borehole using a hydraulic slotting equipment to perform pressure relief and permeability enhancement on a coal seam and enlarge a N.sub.2 (nitrogen gas) or CO.sub.2 (carbon dioxide gas) storage space, injecting a large amount of N.sub.2 or CO.sub.2 into the borehole by means of a high pressure gas cylinder and a pressure reducing valve through a gas injection and extraction pipe, then injecting a certain amount of methane and dry air into a high-temperature and high-pressure combustion chamber by means of the high pressure gas cylinder and the pressure reducing valve, so that the gases are mixed and combusted to form high-temperature and high-pressure impact wave to push a piston to compress the N.sub.2 or CO.sub.2, thereby generating a large number of factures on the coal seam around the impact borehole under guiding action of the slots. The impact wave is repeatedly generated to form a multi-stage impact, and the impact of the next stage is based on the impact of the previous stage, so that the fractures on the coal seam around the borehole are further expanded and run through. After the N.sub.2 or CO.sub.2 is compressed by means of the multi-stage impact, more fracture networks are formed on the coal seam around the borehole under the guiding action of the slots and the fractures, thereby enhancing the borehole-based efficient gas extraction.

A steeply-inclined ultra-thick coal seam gas control method based on a binary composite liquid. The method includes taking a clean fracturing fluid system and a microemulsion as a binary composite liquid. The method includes injecting the binary composite liquid into a coal mass by means of a main hydraulic fracturing and permeability improvement method of hydraulic fracturing and water jet slotting to form a coal mass gas extraction system of binary composite liquid fracturing and permeability improvement. The method includes investigating and analyzing a gas control effect of the steeply-inclined ultra-thick coal seam according to change characteristics and analysis of gas extraction flow rate, change characteristics and analysis of permeability coefficient of coal seam, change characteristics and analysis of gas natural desorption speed of coal mass, change characteristics and analysis of gas concentration of return air flow of working face and theoretical analysis of drilling cuttings index.